Thank goodness Superman isn’t really the last son of Krypton. If that had been held to be unbendable, we never would have got to see various stories showcasing the Kryptonians, whether exploring their culture, history or just being there to challenge Superman.
Their whole back story may have varied over time, but the concept of a race of aliens not too dissimilar to humans but who gain incredible powers under our sun is a great one. With various others appearing over the years to prove that ‘ol Supes isn’t quite as alone as he thought, they always provide entertainment and can set up great drama – whether it’s a long lost cousin, an evil military commander from the Phantom Zone, or a whole lost city being restored. As a race therefore the Kryptonian people can be used to craft great stories, and you only have to look at Superman’s fairly recent run of story arcs involving the restored Kandorians to see how great Kryptonians are in the DC Universe.
Even if you take away the rest of the Kryptonians, you’re still left with Superman and alone he can be really compelling when handled right and worthy of carrying this selection alone.